McArthur River/Key Lake

  • McArthur River/Key Lake, located in northern Saskatchewan, Canada is the world's largest high-grade uranium operation.
  • In July, 2018, due to prolonged market weakness, the operation was placed into safe and sustainable care and maintenance.
  • In service since 1999 and 1983 respectively, Cameco operates the ISO 14001 certified locations, which have collectively produced 535 million lbs using a variety of mining methods.
Operation(As of December 31, 2019)
McArthur River Reserves(As of December 31, 2019)

2019 Q4 Update

Production suspension

The facilities remained in a state of safe and sustainable care and maintenance throughout 2019.

Approximately 175 employees remain at the McArthur River and Key Lake sites. Care and maintenance activities include mine dewatering, water treatment, freeze wall maintenance, and environmental monitoring. In addition, preservation maintenance and monitoring of the critical facilities continues. Our objective is that the McArthur River and Key Lake operations are available to return to production in a timely manner once a decision is made to end the production suspension.

McArthur River/Key Lake Production

Cameco's Share (million lbs)

3 months ended
December 31
Year ended
December 31
2019 2018 2019 2018 2019 Plan 2020 Plan
- - - 0.1 - -1


1. The McArthur River/Key Lake operation is in a safe and sustainable state of care and maintenance.


As a result of the production suspension, there was no exploration activity in 2019.

Labour relations

We reached a new collective agreement with unionized employees at our McArthur River/Key Lake operations. The new agreement expires on December 31, 2022.

Planning for the Future


Due to continued uranium price weakness, we have suspended production for an indeterminate duration. As a result of the suspension, and the time required to restart the mine and mill, we do not expect the operation to produce any uranium in 2020. Our share of the cash and non-cash costs to maintain both operations during the suspension is expected to range between $8 million and $10 million per month. The increase in care and maintenance costs compared to 2019 is related to planned expenditures to fully assess our operating processes. See Innovation below.

Expansion potential

Once the market signals that new supply is needed and a decision is made to restart production, we will undertake the work necessary to optimize the capacity of both the McArthur River mine and Key Lake mill, up to a maximum of 25 million pounds per year (100% basis), the annual production license limit. We expect that this paced approach will allow us to extract maximum value from the operation as the market transitions.


While McArthur River/Key Lake is in a state of care and maintenance, we are taking the opportunity to fully assess our operating processes with the objective of enhancing the efficiency of these operations. Our goal is to streamline our processes and leverage digital and automation technologies to significantly reduce our future operating costs and increase operational flexibility when the time comes to restart. Any opportunities will be rigorously assessed before an investment decision is made.

See full Quarterly Report

Environment & Safety

Worker safety, environmental monitoring and proper decommissioning, after mining is completed, are of the utmost importance to Cameco.

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Reserves & Resources

Our mineral reserves and resources are the foundation of our company and fundamental to our success.

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Caution about forward-looking information

This page may contain forward-looking information that is based upon the assumptions and subject to the material risks discussed on page 2 of Cameco's most recent Quarterly MD&A.